A-level Applied Science/Colour Chemistry

You will need to produce a portfolio of evidence detailing the extraction and application of a natural (plant) dye and the preparation and application of a synthetic dye. You should also include evidence detailing the use of organic pigments in an oil-based paint.

Comment: Although most natural dyes are plant dyes, some are derived from animals or minerals. This is of little consequence to the work, however.

The pigments in oil-based paints are usually inorganic. I have assumed that inorganic pigments for paints are valid. AQA do not give any organic pigments as examples; they suggest hydrated iron (III) oxide, zinc potassium chromate (VI), chromium (III) oxide or iron (III) hexacyanoferrate (II) (Prussian Blue).